Overcasting presser foot for zig-zag sewing machines



R. E. MILLER 2,950,696

OVERCASTING PRESSER FOOT FOR zIG-ZAG SEWING MACHINES Aug. 30, 1960 Filed April 18, 195e I6 11 Fiel.

Il IZ L INVENTOR. Rum E. MILLER ATTORNEY x 2,959,696 Patented Aug. 30, 1960 ice GVERCAS'UNG PRESSER FOOT FOR ZiG-ZAG SEWING MACHINES Ruby E. Miller, Hollywood, Fla., assigner to Howard R. Lott, Hollywood, Fla.

Filed Apr. 18, 1958, Ser. No. 729,325

1 Claim. (Cl. 112-235) This invention relates to an overcasting presser foot for use on zig-zag stitching machines, and has particular reference to a presser foot for producing overcasting work or stitches over the edge of textile fabrics as a means to prevent raveling of the material as well as to give finished look where raw seams are objectionable. While the device is primarily designed for use with a household sewing machine, it is by no means restricted to such use and may be readily varied to accommodate itself to commercial sewing machines.

Zig-zag stitching commonly employed for protecting the edges of fabric against raveling is well known in the art, but the zig-zag stitching heretofore created has been objectionable in thart the zig-zag stitches as they are formed, draw the thread relatively tight from one position of the needle to the other, imparting a tension upon the thread that causes the edge of the fabric to roll and fail to present a completely dat surface, so desirable and necessary in the finishing of seams.

The invention further contemplates a presser foot having a connector arm whereby the foot is readily attached to the presser bar of the sewing machine and with the presser foot being centrally triangularly apertured to accommodate the needle in its up and down and lateral motions and with the aperture being bisected by a tension control prong that causes a loose overcasting of the thread as the needle moves from one side of the apenture to the other and whereby to impart sufficient looseness to the thread that will subsequently slide from the prong as the material is fed rearwardly and thus relieve the heretofore objectionable tension upon the thread, creating a zig-zag stitching upon the marginal edge of the fabric that will permit the edge to lie iiat.

Novel features of construction and operation of the device will be more clearly apparent during the course of the following description, reference being had to the accompanying drawings wherein has been illustrated the preferred embodiments of the device and wherein like characters of reference are employed to denote like parts throughout the several figures.

In the drawings:

Figure l is a perspective view of an overcasting presser foot for zig-zag stitching machine and embodying the invention,

Figure 2 is a plan view thereof,

Figure 3 is a bottom plan View thereof,

Figure 4 is a longitudinal section taken substantially on line 4 4 of Figure 2,

Figure 5 is a transverse section taken substantially on line 5 5 of Figure l,

Figure 6 is an end view illustrating a slightly modied form of the device and,

Figure 7 is a section taken substantially on line 7-7 of Figure 6.

Referring specifically ,to the drawings, the numeral 5 designates the presser foot as a whole, embodying a generally rectangular foot portion 6, preferably formed .of plastic although, other materials may be employed if so desired. The foot `6 at its forward end is notched at 7, forming guide edges 8 whereby the device functions to guide the material in accurate alignment with respect to the zig-zag needle, not shown. The tongues 9, formed by the notch 7 are rounded or beveled rearwardly from their terminal ends as at 10 and whereby the material may be easily fed beneath the foot 6. The foot 6 is further provided with ears 11, to which is pivotally connected as at 12 a conventional arm 13, whereby the device is connected with the presser bar of the sewing machine. The arm 13 may be varied in construction to accommodate itself to the various forms of zig-zag stitching machines commonly in use. The pivots 12 for the arm 13 permit a limited pivotal movement of the arm with respect to the presser foot 6 whereby the presser foot may readily accommodate itself to the surface of the materials being stitched.

The presser foot 6 substantially centrally thereof is triangularly apertured at 14 and this aperture 14 is rearwardly undercut as at 15. The aperture 14 is formed rearwardly of a web portion 16, formed between the notch 7 and the aperture 14. The web 16 is cut away along the lines 17, for the reception of a head portion 18, of a tension control prong 19. The head 18 is of substantially the same thickness as the web 16 and is cemented or otherwise firmly connected into the opening formed by the cut out of the web 16. The prong 19 has a flat lower face 2i! that is flush with the bottom of the presser foot. The prong 19 is longitudinally tapering rearwardly to substantially a point 21. The upper surface of the prong, as clearly shown in Figure 5 is rounded transversely from the head 18 to the point 21. The prong 19 extends longitudinally of the presser foot and substmtially centrally with respect to the aperture 14 and terminates beneath the undercut 15 at the apeX of the triangle. As shown in Figure 4, the point 21 terminates in spaced relation to the apex of the triangle to form a clearance betweenthe body of the presser foot and the prong for permitting the overcast stitches to progressively slide from the prong as the material being stitched is fed rearwardly. The needle in a Zig-Zag action engages alternately through the wider portion of the aperture 14 upon opposite sides of the prong 19, as indicated in dotted' lines in Figure 3 at 23. The rear end of the presser foot is also 1rounded transversely at 24 and with the presser foot having no abrupt edges that will tend to catch into the material or tend to drag the material as it is fed rearwardly. While the prong 19 is shown as an assembled element with respect to the presser foot, it will be clearly apparent that the prong 19 may be molded as an integral element with the foot 6.

In the use of this form of the invention, the presser foot having been engaged with the presser bar and firmly set by the conventional set screws, the foot is lowered to the operative position with respect to the conventional feedv mechanism. The material is then fed beneath the presser foot with one edge 8 constituting a guidefor the edge of the material being fed therebeneath. The machine is placed in motion and the needle 23 imparts the zig-zag motion transversely of the presser foot, drawing the thread over the surface of the prong 19 back and forth under the motion of the needle and, as the material is fed rearwardly by the feed mechanism, the loops formed by the passage of the thread over the prong, progressively feed rearwardly over the prong and slide therefrom. The forming of the loops over the prong 19 create su'icient looseness in the stitching as will avoid am tendency of the stitching to `curl the edge of the material, such being a commonly objectionable feature with zig-zag stitching machines presently in use. The

opposite guide edge S is employed where the material is reversed and forms an accurate guide to enable the operator to feed the material in an accurate line tom either side.

In the form of the invention illustrated in Figures 6 and 7, ,ther structure is substantially the same as that preeY Viously illustrated and described.- However, inQthis/form of the invention, the prong 19a is pivotally supportedlin the opening formed bythe cut out 17, by a pin 20a that passesY transversely throughthe presser foot and through the head portion18a Vof the prong. As 'clearly shown in Figure 6, the head 18a is provided upon its, opposite sides with stop shoulders-181; while stop shoulders 18e are Vformed upon the side walls of the cut out ,17, such shoulders serving to permit the relatively oating motion Y for the prong `19a to rise and fall toalirnited degree for accommodating itself tothe fabric being stitched. A slight motion of the prong 19aris illustrated in one position in dotted lines in Figure 7,'whi1e they prong may fall a corresponding distance beneath the lower surface of the foot ats-determined by the shoulders 1812 and 18C. The operation of this form of the invention is substantially identical to that previously described.

Itwill be Vapparent from the foregoing that a very novel form of presser foot for overcasting with zig-zag stitching has Ybeen employed. T he device as shown creates a very desirable zig-zag stitching to protect the cut edgesY of fabric against raveling and creates the zig-zag stitchingrin a manner that Vprevents any tendency of the edge to curl. By controlling tension of the stitch, edge is suiciently at so no ridge or mark shows through to right side when pressed or ironed as is the case when regular zig-zag foot is used. Since stitches are formed over tension control prong rather than material itself, this is equally adaptable on any weight maferial from thin organdy to heavy Woolens or felts. Where thread tension control presser foot is used, overcasting stitches are slightly wider than with regular zig-zag presser foot. In using for finished seam effect rather thanA just to prevent raveling a smaller stitch setting on zig-zag machine is used so as to give satin stitch eiect over edge of seams. The structure is simple, is economically formed and is highly successful.

It is to be understood that the invention is not limited to the precise construction shown, but that changes are contemplated as readily fall within `the spirit of the invention as shall be determined by the scope of the subjoined claim.

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

An overcasting presser `foot for zig-zag Vsewing machines of the type adapted to produce zig-zag stitching along the marginal edges of fabric to prevent raveling and to form a finished appearance, comprising a at foot portion, means for hingedly suspending the foot portion from a presser bar of the sewing machine to have overriding engagementy with fabrics to be stitched, the foot at its forward end being notched intermediate its width to form a pair of projecting tongues, the inner edges of each of the tongues constituting guides for the edge portions of the fabric to; be` stitched, the foot intermediate its width and rearwardly of the notchV being cut away to form a triangular opening, the opening adapted to be traversed from side to side by a zig-zag needle of the sewing machine, a thread tension control prong that is connected to the foot at a position intermediate the width ofthe opening, Ythe said prong extending rearwardly to substantially bisect the opening, the said prong adaptedY to receive loops of thread being formed by the zig-zag needle in its side to side motion and Whereby the thread -loops are engaged over the Vprongs progressively as the fabric. is fed rearwardly beneath the foot, the prong at its terminal end being spaced from a rear apex of the opening la distance capable of permitting the loops of thread -to slide therefrom to be fed beneath f the foot as the fabric is fed rearwardly, the said thread loopsas they slide from the prong being relieved of tension rthat would cause the stitched edge of the fabric to curl, the said prong being provided with a head portion that is hingedly connected with respect to the foot and stop means formed upon the foot and the head portion whereby the prong may swing in a vertical plane References Cited in the le of this patent UNITED STATES PATENTS Baehr Feb. 21, 1956 

